Method of making plastic scintillation



2,733,216 Patented Jan. 31, 1956 Fice United States Patent Oli METHOD or MAKING PLA G'eollrey G. Eichholz and John tano, anad the right of STIC SCINTILLATION PHOSPHORS a, assignors to Her Canad es and Technical Surveys No Drawing. Application May 7, 1953, Serial No. 353,668

2 Claims. (Cl. 252-3012) This invention rel the conversion of high energy radiat to act upon a photomultiplier tube,

a, as represented Horwood, Ottawa, On- Majesty the Queen in by the Minister of ates to phosphor elements, useful in ions to fluorescent light or similar lightsensitive device, in order that 'the amount of radiation emanating from an ore or be measured readily,

producing such elements.

they are available.

The object of the the manufacture of which are relatively cheap, qui

tured, very rugged inside the mixture. corporation of the Hydrocarbon com 1 orescence agents in as terphenyl, fluor anthracene, xylene,

ared in any mechanically,

any other and to an elfective method of radioactive source size and shape as desired,

ckly and easily manufacand very stable over a umidity conditions.

Under these conditions uniform influorescence agent or agents into the and a clear, bubble-free obtained without the use of catalysts pounds which may be used as fluclude many aromatic compounds such ene, chrysene,

toluene, and re phenanthrene, indene, lated substances. Flusize of phosphor unit desired. Within the styrene. 7%

response well above 4000 A.

It will be apparent that during the formation of the solid solution the mass may be moulded into any desired machining the finished plastic into round or tapered forms, a feature no crystalline phosphor possesses. Short cylinders of to absorb most Grams (2) Styrene 50 Fluorene 3 Diphenylhexatriene 0.005

may be moulded We claim: 1. A method of detection and producing of a hydrocarbon fluorescence-producing material and an agent which shifts the uorescence spectrum into the visible region, placing the mixture in a moulding zone, heating the mixture to a tem- 3,2 6 perature of 85 to 195 C. under a pressure of 1099-2000 References Cited in the file of this patent Ye 4:000 20,000 UNITED STATES PATENTS p. s. i. to expel air, raising the pressu s i and heating the mass at a temperature in excess of the melting point of the phosphor material and not low- 2559319 Ludeman er thig the nrma1dcuri g tempegatgre of the polystyrertie 5 O H REFERENCES to e ect um orm lstrl 1111011 0 t e components in t e PolYStYrene and form a uniformly clear product and ssggg f i g g g i fi g 3 222: 3";

cooling the mass to solidify it in the desired structural pticle Phys Review vol Ap 15 form ' 1951. 230-232. Co .Lb.

2. The method defined 1n clann 1 wherein diphenyl 10 gg s f g gzl ig Pglyzners, 1952, Rein- Shfimg hold Pub. 00., page 1067. (Copy in Sci. Lib.)

hexatriene is the fluorescence spectr Eichholz: Rev. of Sci. Instr., vol. 23, No. 6, page 305,

July 3, 1951 June 1952. (Copy in Sci. Lib.) 15 Chou: Phys, Rev., vol. 87, No. 2, pp. 376, 377, July 

1. A METHOD OF PRODUCING PHOSPHOR UNITS FOR USE IN THE DETECTION AND MEASUREMENT OF PENETRATING RADIATION, SUCH AS GAMMA RAYS, WHICH COMPRISES FORMING A MIXTURE OF POLYSTYRENE MOULDING POWDER, 0.2 TO 20% OF ITS WEIGHT OF A HYDROCARBON FLUORESCENCE-PRODUCING MATERIAL AND 0.002 TO 0.05% OF ITS WEIGHT OF AN AGENT WHICH SHIFTS THE FLUORESCENCE SPECTRUM INTO THE VISIBLE REGION, PLACING THE MIXTURE IN A MOULDING ZONE, HEATING THE MIXTURE TO A TEMPERATURE OF 85 TO 105* C. UNDER A PRESSURE OF 1000-2000 P.S.I. TO EXPEL AIR, RAISING THE PRESSURE TO 4,000 TO 20,000 P.S.I., AND HEATING THE MASS AT A TEMPERATURE IN EXCESS OF THE MELTING POINT OF THE PHOSPHOR MATERIAL AND NOT LOWER THAN THE NORMAL CURING TEMPERATURE OF THE POLYSTYRENE TO EFFECT UNIFORM DISTRIBUTION OF THE COMPONENTS IN THE POLYSTYRENE AND FORM A UNIFORMLY CLEAR PRODUCT AND COOLING THE MASS TO SOLIDIFY IT IN THE DESIRED STRUCTURAL FORM. 